Currently, dismounted troops have the capability to effectively breach medium weight steel doors using rifle-launched stand-off breaching devices such as the SIMON device and a similar U.S. Army derivative the GREM. Attempts are currently underway to develop a similar stand-off breaching capability which may be fired from a 40 mm grenade launcher. The 40 mm grenade is known as the Hell Hound. Both of these platforms have their advantages and disadvantages.
The SIMON is effective, but is not a compact device.                Weight: 680 g (including stand-off rod)        Length:        Stand-off rod: 400 mm        Overall: 765 mm (30 inches)        Warhead diameter: 100 mm        Explosive fill:                    Standard SIMON: 150 g (PBXN-109)            SIMON 120: 120 g (PBXN-109)                        Range: 15-30 metersOne of the most significant disadvantages of the SIMON device, and a significant cause of its lack of compactness, is its stand-off rod. The stand-off rod causes the SIMON device to be at least a certain distance from a door when its explosive detonates.        
The 40 mm grenade (Hell Hound) is compact, but its effectiveness is limited by its maximum payload and by the fact that it explodes on impact. A typical Hell Hound grenade has the following characteristics:                Weight: 225 grams        Length: 110 mm (4.3 inches)        Explosive fill: 88 grams (A5)        Range: 400 mHell Hound grenades appear to be limited to a maximum explosive fill of less than 90 gram. Furthermore, as noted, the Hell Hound detonates on impact and does not rebound from the target, thereby preventing it from achieving an optimal stand-off distance.        
What is needed is a stand-off breaching device that combines the breaching effectiveness of the SIMON device and GREM with the compactness of the Hell Hound. To be effective, such a stand-off breaching device should produce minimal fragmentation and minimal blast hazards for the operator.